1. Technical Field
The present invention relates to a method for the production of a hollow particle having plural spaces formed inside thereof.
2. Description of Related Art
Hollow particles with a dense shell on the surface having a single spherical space or consecutive minute spaces formed inside thereof, have been developed as a functional member for providing thermal insulation, lightweight property and the like. The hollow particles can exhibit higher effects on thermal insulation and lightweight property as the hollowness is higher, but as the hollowness is higher, strength of the shell decreases. Thus, hollowness may not be obtained in some cases because dense shells cannot be formed on the surface in the molding of the particles, or the hollowness may be lost in the use of the produced hollow particles due to shell damage and the like.
In order to solve such problems, hollow particle having fractionated plural spaces, but not a single spherical space nor consecutive spaces, formed inside have been proposed.
For the hollow particle having plural spaces formed inside thereof, strength of the hollow particle increase by the presence of partitions dividing each space, and further even if a part of the surface wall exposed to the surface is damaged, loss of hollowness is limited to the part.
As a method of producing such hollow particle, for example, a method which comprises forming resin particles for a shell from a foaming material, and then foaming the resin particles (for example, see JP-A-2012-201825).